Computing system



Jan. 2, 1945. H. G. JOHNSTONE COMPUTING SYSTEM Filed March 15, 1930 ll Sheets-Sheet 1 OOOOOOOOA UOOOQOOOOOQO wwN H 1945 H. G. JOHNSTONE 2, 3

COMPUTING SYSTEM Filed March 15, 1930 ll Sheets-Sheet 2 ww. W

Jan. 2, 1945. H. G. JOHNSTONE COMPUTING SYSTEM Filed March 15, 1930 11 Sheets-Sheet 4 In a i Jan. 2, 1945. JQHNSTQNE 2,366,193

COMPUTING SYSTEM Filed March 15, 1930 ll Sheets-Sheet 5 knew/0r 6. Jaws/0x75 /293 Wmy. I

Jan. 2, 1945. H. G. JOHNSTONE COMPUTING SYSTEM Jan. 2, 1945. H. G. JOHNSTONE COMPUTING SYSTEM 11 Sheets-Sheet '7 Filed March 15, 1930 \NM wk mww wwwza/ A. 6. J0/7/75/d/76 WMX/Wy Jan. 2, 1945. H. e. JOHNSTONE COMPUTING SYS TEM Filed March 15, 1930 ll Sheets-Sheet 8 Jan. 2, 1945. 4 JQHNSTONE 2,366,193

COMPUTING SYSTEM Filed March 15, 1930 ll Sheets-Sheet 9 as I F n i q. 7 2- Wye/71W 6/ 6. Jams/047a 1945- H. G. JO HNSTONE 6, 3

COMPUTING SYSTEM Filed March 15, 1930 ll Sheets-Sheet 1O Jan. 2, 1945- H. 5. JOHNSTONE COMPUTING SYSTEM Filed March 15, 1950 ll Sheets-Sheet ll v M M 0 n w m 7 T A w MW 3 J e H 3 3 a a W 2 6 w Patented Jan. 2, 1945 COMPUTING SYSTEM Harold G. Johnstone, Oak Park, Ill., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application March 15, 1930, Serial No. 436,135

34 Claims.

This invention relates to computing systems, and more particularly to an electrically operated, mathematical multiplication system operative to perform a computation in accordance with information appearing on record sheets and record the result of such computation.

An object of the present invention is the provision of a relatively simple system for accurately and rapidly performing computations in accordance with information in a record member and recording the result'of such computations.

In accordance with one embodiment, the invention contemplates a unitary system including mechanism for automatically and successively advancing perforated record sheets to a sensing head which receives information from the sheets and which transmits it to an electrical multiplying apparatus in which a computation is effected in accordance with the information recorded on each sheet. The result of the computation is then transmitted electrically for operating a perforating apparatus to record the result. in terms of the allocation of perforations. Coordination of the system is made possible by the advancement of the record sheet from the sensing head to the perforating apparatus in timed relation to the actuation of the various mechanisms of the system.

These and other objects of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein Figs. 1 and 2 are a general plan view and a fragmentary front elevational view respectively, of the apparatus;

Fig. 3 is a fragmentary horizontal sectional view, taken substantially on the line 3-3 of Fig. 2 in the direction of the arrows;

Figs. 4, 5, and 6 are fragmentary vertical sectional views, taken on the lines 4-4, 5-5, and 6-6, respectively, of Fig. 3 in the direction of the arrows;

Figs. 7 and 8 are detailed plan and side elevational views of the record sheet advancing mechanism;

Fig. 9 is a fragmentary vertical sectional view, taken on the line 9-9 of Fig. 2 in the direction of the arrows showing the electrical multiplying mechanism;

Figs. 10 and 11 are vertical sectional views taken on the lines ill-40 and il-ll respectively, of Fig. 9 in the direction of the arrows;

Fig. 12 is a vertical sectional view, taken on the line l2-l2 of Fig. 11 in the direction of the arrows;

of a part of the electrical multiplying mechanism;

- Fig. 19 is a fragmentary sectional view taken on the line IQ-IS of Fig. 9, and

Figs. 20 and 21 are fragmentary sectional views taken substantially along the lines 2ll--20 and 2 |-2l in the direction of the arrows.

Referring now to the drawings wherein like reference characters designate similar parts throughout the several views, the numeral I designates generally a housing, which encloses the moving parts of the mechanism, and which is mounted upon a base 2, upon and within which are positioned the principal elements of the apparatus. For the sake of simplifying the disclosure, the apparatus will'be divided into four principal parts; namely, a card feeding mechanism, designated generally by the numeral 3 and shown in Figs. 4, 5, 7, and 8, a sensing mechanism designated generally by the numeral 4, and shown in detail in Figs. 3 and 4, a multiplying mechanism, designated generally by the numeral 5 and shown diagrammatically in Fig. 3 and in detail in Figs. 9 to 13 inclusive, and a card perforating mechanism, designated generally by the numeral 6 and shown in Figs. 3 and 5.

The base 2 is mounted upon suitable standards 1 (Fig. 2), and has secured to the bottom surface thereof an electrical motor 8 connected through a shaft 9 to a speed reducing mechanism H) from which extends a shaft l8, which serves as the main drive shaft for the moving parts of the apparatus. The shaft 16 extends upwardly through the base 2 and has mounted intermediate its ends a bevel gear N (Fig. 6), which meshes with a bevel gear i8 mounted upon a shaft l9 which extends longitudinally of the apparatus. The shaft I9 is journaled in bearings 20 and 2! and carries, adjacent the bearing 2|, a gear 22 from which the multiplying mechanism 5, to be described in detail hereinafter, is driven. The gear 22 meshes with an idler gear 23 (Fig. 3). which in turn meshes with a spur gear 24 mounted upon a shaft/25 which drives the record card advancing mechanism.

The upwardly extending portion of the shaft I6 has slidably keyed thereto a toothed clutch member 26 adapted to engage a cooperating toothed clutch member 21. The clutch member 26 is normally urged upwardly by a compression spring 28 which surrounds the shaft I6 and is positioned between the lower surface of the member 26 and the gear I1. A collar 29 formed on the clutch member 26 is engaged by a yoke 30 pivoted to a supporting member 36 at 3| and provided with a projecting portion 31 adapted to be engaged by a latch 38 formed on a spring pressed armature 39 of an electromagnet 40, which is also supported by the supporting member 36. Upon energization of the electromagnet 40 the armature 39 will be attracted to release the latch 38 from the projecting portion 31 of the yoke 30 thereby to permit the spring 28 to move the clutch member 26 into engagement with its associated clutch member 21. Clutch member 21 is freely rotatable about the shaft I6, being held against vertical movement thereon by a collar 4I pinned to the shaft I6 at 42 and a shoulder 43 formed on the shaft I6 between which and a recessed portion 44 of the clutch member 21 a washer 45 is interposed.

Formed on the clutch member 21 is a beveled gear 46 which meshes with a beveled gear 41 mounted on a cam shaft 48. The cam shaft 48 is journalled at 49 and 50 in the supporting member 36 and a supporting member 56, and carries a plurality of cam wheels 51, 58, 59, 6I, 62, 63, 64, and 65, the purpose of which will be described in detail hereinafter. The cam wheel 51 constitutes a control means for resetting the latch 38 which controls the operation of the clutch member 26 and is so formed that once during each revolution of the cam shaft 48 it will actuate a cam member 66 which is slidably mounted in apertures 61 and 68 formed in brackets 69 and mounted upon the supporting member 36. Upon actuation of the cam member 66 downwardly, the electromagnet 40 having been de-energized, the yoke 30 will be moved downwardly to compress the spring 28 and permit the latch 38 to engage the projecting portion 31 formed on the yoke 30 to lock the clutch member 26 out of engagement with the clutch member 21 until the electromagnet 40 is again energized. From the foregoing, it will be apparent that upon energization of the electromagnet 40 the clutch members 26 and 21 will be brought into engagement to drive the cam shaft 48 through one revolution, whereupon the clutch members will be disengaged through the actuation of the cam 61 which will restore to its normal position the armature of electromagnet 40.

A magazine designated generally by the numeral 16 (Figs. 1, 2, 3 and 4), and adapted to receive a supply of cards 11 (Fig. 4) is positioned at the front of the apparatus and comprises side walls 18 and 19, a rear wall 80, card retaining members 6| and 82, fixed to the side walls at their front ends, and a base 83. The magazine 16 is mounted upon a supporting member 84 and has-a slot 85 cut in its rear wall 60, through which one of the cards 11 may be advanced by a pick-up finger 86 which has a projecting portion 81 extending above the base 83, a distance such that it will, upon being reciprocated, engage only the lowermost card. A suitable slot is provided in the base 83 in which the pick-up finger 86 may be reciprocated to advance a card through the slot 85 in the rear wall of the magazine, and a stop 88 is secured to the rear wall and is adjustable so as to permit only one card at a time to be advanced through the slot.

Secured to the underside of the pick-up finger 86 (Fig. 4) is a depending member 89 to which is pivoted a link 90, the other end of which is pivoted to an upwardly extending arm of a bell crank lever 96. The bell crank 96 is rotatable about a shaft 91 mounted in the supporting member 84, and has its horizontal arm pivoted at 98 to a link 99 which is secured at its upper end to a bell crank lever I00. The bell crank I00 carries at its lower end a cam roller I02 (Fig. 3), which engages the face of the cam 59 and is pivoted on a crank supporting rod I 0| which extends between supporting members 36 and 56. Once during each revolution of the cam shaft 48, the cam 59 will, through the cam roller I02, move the bell crank lever I00 in a clockwise direction and thereafter in a counterclockwise direction (Fig. 4), to reciprocate the pick-up finger 86, thereby causing it to pick a card from the bottom of the magazine 16, and advance it through the slot into engagement with a pair of cooperating upper and lower card feed rollers I03 and I04 respectively (Fig. 4).

The card feed rollers I03 and I04 are mounted upon shafts I05 and I06 (Figs. 4, 7 and 8). The shaft I06 (Figs. 7 and 8) is journalled in side plates I01 and I08 mounted upon the base 2 and the shaft I05 is journalled in journal blocks I09, which are slidable vertically in slots H0 and H6 formed in the side plates I01 and I08 respectively, the blocks being urged downwardly by springs H1.

The card feed rollers I03 and I04 are the first of a chain of card feed rollers, which serve to advance cards one at a time through the apparatus. In this series of card feed rollers, the lower rollers designated I04, IIB, I20, I2I, I22, I23, I24, and I25, are driven constantly from the rotating shaft 25, worm gears I26, I21, I28, I29, I30, I3I, I32, and I33 being pinned to the shaft 25 and meshing with worms I34, I35, I36, I31, I38, I35, I40, and HI, mounted on shafts I06, I42, I43, I44, I45, I46, I41, and I48, respectively, which have the card rollers mounted thereon. The shafts I42, I43, and I44, are journalled in the side plates I01 and I 08 and have secured thereto the card rollers H9, I20, and I2l, respectively, which extend through a base plate I52 secured to the supporting member 84 (Fig. 4) and through a movable base plate I53 positioned between the side plates I01 and I08, and normally having its upper surface on the same plane as the upper surface of the base plate I52. The shafts I45, I46, I41 and I48 are journalled in side plates I54 and I55 and have mounted thereon the card feed rollers I22, I23, I24 and I25, respectively, which extend through a base plate I66 positioned between the side plates I54 and I55, and a base plate I56 supported by a bracket 51 connected to the side plates I54 and I55.

It will thus be apparent that the lower card feed rollers are all positively driven in a clockwise direction (Fig. 8), and would normally tend to advance a card which has been moved into engagement with the first set of rollers I 04, but the upper cooperating card feed rollers are not all positively driven, and card stopping mechanism, to be described hereinafter, serves to interrupt the movement of a card through the apparatus. The upper card feed rollers I03 mounted upon the shaft I05 are positively driven for the shaft I05 has mounted at one end thereof, a worm gear I61 which meshes with the worm I34 (Fig. 7) 118,111, I18, and,

being urged into engagement therewith by the springs II1.

A pair of upper card feed rollers I58 and I69 which cooperate with the lower card feed rollers I2I and I24, respectively, are constructed in the same manner as the upper card feed roller I and like the card feed roller I05 are positively driven in a counterclockwise direction (Fig. 8).

Cooperating with the lower card feed rollers H9, I20, I22, and I23, are upper card feed rollers I19, respectively, r0- tatably mounted on the ends of stud shafts I80, I8I, I82, and I83, secured to' the vertically disposed arms of hell crank levers I84, I85, I86, and I81, respectively. The bell crank lever I84, I85, I86, and I81, are rotatably mounted in brackets I88 formed on the side plates I01, I08, I54, and I55, and the upwardly extending arms thereof are pinned to reciprocable connecting members I89 which have their left hand ends (Figs. 7 and 8) pinned to levers I90 at IS. The levers I90 are keyed to a shaft I96 to which is also keyed a lever I91, having connected to the end thereof a link I98 (Figs. 4, 7 and 8). The link I98 is at its upper end connected to an arm of a bell crank lever I99 mounted on the crank supporting rod IOI and carrying on its other arm a cam roller 200which engages the surface of the cam 6I mounted on the cam shaft 48. Once in each revolution of the camshaft 48 the cam 6| will move the bell crank I99 in a clockwise direction to impart a reciprocatory motion to the connecting member I89. Movement of the connecting member I89 will cause the bell cranks I84, I85,

I86, and I81 to move the upper card feed rollers I16, I11, I18, and I19 out of engagement with their cooperating lower card feed rollers.

Simultaneously with the movement of the upper card feed rollers I16, I11, I18, and I19 out of engagement with their cooperating lower card feed rollers, stop members 2M and 202 will be moved into the path of advancing cards and will serve to position accurately the cards in the sensing mechanism 4 and the perforating mechanism 6, respectively. Movement of the card stops I and 202 into the path of advancing cards is effected by the following mechanism: The card stops 20I are pinned to a shaft 203, journalled in the side plates I01 and I08 and the card stops 202 are pinned to a shaft 204, journalled in the side plates I54 and I55. The shafts 203 and 204 have secured thereto depending levers 205 and 206, respectively, which are at their lower ends connected by a link 201 (Fig. 8). The shaft 204 also has keyed thereto a lever 208 at the left hand end of which ispivoted an upwardly extending link 209, whose upper end is pivoted at 2I0 (Fig. 3) to a horizontal extending arm of a bell crank 2 I6 rotatable about the crank supporting shaft 2l1 and carrying on its vertically extending arm a cam roller 2I8 which'engages the surface of the cam 58.

The card feeding mechanism 3, as described hereinbefore, will, upon each rotation of the cam shaft 48, move the card stops 20I and 202 out of the path of a card which will be advanced by the upper and lower card feed rollers into position in the sensing and perforating mechanisms, whereupon the card stops 20I will be moved into the path of the card being advanced from the magazine, and the card stops 202 will be moved into the path of the card being advanced from the sensing mechanism accurately to position them in t% sensing and perforating mechanisms respectively, and just subsequent to the movement of the card stops into the path of the cards, the cam 6| will move the upper card feed rollers I16, I11, I18, and I19 out of engagement with the cards. It will be apparent from the foregoing that cards will be advanced from the magazine 16 step by step through the apparatus until they come into engagement with the constantly driven card feed rollers I69 and I24 which will advance them to the lower card feed roller I25 and cooperating upper card feed rollers 2I9 which are mounted upon a shaft 220, having worm gear 22I formed thereon which meshes with the worm gear I4I. A card, upon engaging the upper card feed rollers H9 and the lower card feed rollers I 25, will be directed thereby to a chute 222 which will direct them into a receiving hopper 223 (Fig. 5).

The sensing mechanism 4 to which a card is advanced from the magazine 16 and in which the card is accurately positioned by the card stops 20I comprises a pair of heads 225 and 226 (Fig. 6), the movable base plate I53, the upper portion of which is composed of an insulating composition and has embedded therein a plurality of contacting members 224 (Fig. 4) of conducting material. There are provided 45 of the contacting members 224 in the base plate I53 positioned so that one contact member will be directly under each of 45 rows of possible perforations in a record sheet of the type commonly used in tabulating machines, in which there are 45 rows in each of which rows any one of ten possible positions may be perforated. Each of the contacting members 224 is connected through a conductor 221 associated therewith, to the multiplying mechanism as described hereinafter.

The movable base plate I 53 forms a part of a casting 228 which is slidable vertically on a pair of guide rods 229 secured to the base 2. Positioned around the guide rods 229 between the casting 228 and the base 2 are a pair of compression springs 230 which urge the casting to move upwardly on the guide rods 229. This movement of the casting 228 upwardly is controlled by a lever 236 which is secured to a shaft 231 journalled in brackets 238 and 239 mounted on the base 2. Secured to the other end of the shaft 231 is an arm 243 to the end of which is pivoted one end of a link 244, having its other end piv otally attached to an arm of a bell crank lever 245. The other arm of the bell crank lever 245 has mounted thereon a cam roller 246 which engages and is actuated by the cam 62. Once in each revolution of the shaft 48 the cam 82 will permit its cam roller 246 to be moved into closer association with the cam shaft 48 by the springs 230, which will thereupon move the movable base plate I53 upwardly a predetermined amount to take information from a perforated record card positioned thereon.

The45 contacting members 224 are individually connected to 45 associated jacks 25I (Figs. 2 and 14) mounted in a switchboard 252 positioned on a base 2 at the front of the machine, any 12 of which may be connected by double ended cords 253 to jacks 254 and 255 connected to the multiplying machine mechanism as'described hereinafter.

The sensing heads 225 and 226 which cooperate with the contacting members 224 to sense a card and take information therefrom, are boxlike structures (Figs. 4 and 6), which are slidable transversely of the sensing mechanism 4 on rods 241 and 248 (Figs. 3 and 4), fixed to the supporting members 36 and 56. An upwardly extending portion 249 of the sensing head 225 has a threaded aperture 250 formed therein in which is threaded a rod 256 journalled in the supporting members 36 and 56 and adapted to be rotated by means of a. hand crank 251 secured thereto. In like manner a threaded rod 258 journalled in the supporting members 36 and 56 engages a threaded aperture 259 in an upwardly extending portion 260 of the sensing head 226 and may be rotated by means of a hand crank 26 l. The threaded rod 256 passes through an aperture 262 in the sensing head 225 and the threaded rod 256 passes through an aperture 263 in the sensing head 226. The sensing heads 225 and 226 may, by proper manipulation of the hand cranks 251 and 261, be moved either to the right or to left (Fig. 3), and their position will be indicated by pointers 264 and 265 which are attached to the sensing heads 225 and 226 respectively (Figs. 3, 4, 5, and 6), and which cooperate with an indicating scale 266 mounted on the housing I (Figs. 1 and 5).

The sensing head 226 has provided in its upper and lower surfaces (Fig. 4), a plurality of apertures 261 and 268 respectively, in which are slidably positioned a plurality of sensing pins 269 which have formed thereon shoulders 210 for preventing movement of the pins downwardly beyond a predetermined point. springs 21l being provided to urge the pins l69 downwardly. There are provided six rows of nine each of the pins 269, the rows being spaced apart a distance corresponding to the spacing of the contacting members 224 with which they are associated. These pins are adapted to make a sliding contact with the contacting members 224 through apertures in a card which has been advanced onto the movable base plate [53, to complete electrical circuits therethrough to the multiplying mechanism to be described hereinafter.

The sensing head 226 also carries a plunger 218 Figs. 4 and 6), which actuates a contact spring 211 to close contact between it and an associated contact spring 218. each time the movable base plate 153 is moved upwardly while a card is positioned thereon, a slot 219 being provided in the movable base plate I53 into which the plunger 216 will pass when no card is positioned on the base plate.

The sensing head 225 is the same as the sensing head 226 except that it has no plunger similar to the plunger 216, and therefore it is not believed to be necessary to describe the sensing head 225 in detail.

The sensing heads 225 and 226, each being provided with six rows of sensing pins 269 and each being limited in movement transversely of the base plat I53 only by the other, it will be apparent that, considering the 45 contacting members 224 as being numbered 1 to 45 from right to left (Fig 6), the sensing head 226 may be associated with an six contacting members 224 from 1 to 89 and the sensing head 225 may be associated with any six contacting members 224 from 7 to -15. Each row of sensing pins 269 represents the digits 1 to 9 in a denominational column which may either be units U, tens T, hundreds H, ten hundreds TH, ten thousands TT, or hundred thousands HT, and the rows associated with the digit 1, 2, 3, 4, etc. are connected to common conductors: that is, the sensing pins 269 representing the digits 1 in all of the denominational columns are connected to a common conductor, the pins representing the digits 2 in all of the denominational columns are connected to a second common conductor, etc, through the digits 9.

Referring now to Figs. 14 and 15, the group of coordinated lines designated 30I represents schematically the sensing head 225 and any six contacting members 224 with which the sensing head may be associated and for the sake of simplicity, will be termed the multiplicand bank 301, since it will be assumed that the contactin members 224 associated with the sensing head 225 have been connected through their associated jacks 280. and the double ended cords 28l to the jacks 292 which are connected to the multiplicand part of the multiplying mechanism. In like manner the group of lines designated 302 represent schematically the sensing head 225 and any six contacting members 224 with which it may be associated, this group of lines being hereinafter termed the multiplier bank.

In the multiplier bank 302 the vertical lines or columns from left to right denote units U, tens T, hundreds H, ten hundreds TH, ten thousands TT, and hundred thousands HT, and the nine rows of horizontal lines designate the digits 1 to 9 consecutively, from top to bottom. Each intersection of the lines represents an electrical contact in the sensing head 225 or 226 which is normally open, but which will be closed it the sensing pins 269 associated with that particular digit registers with an aperture in the position allocated thereto on the record card and engages the contacting members 224 associated therewith.

Any particular problem of multiplication can be transmitted to the multiplying mechanism 5 by the closure of contacts at the points corresponding to the digits in the multiplicand and multiplier as indicated in the multiplier and multiplicand banks 302 and 30!. The closure of these contacts completes electrical circuits through a multiplying commutator 303 and sends electrical currents to a distributor switch denoted generally by the numeral 304, which directs the currents to an accumulator 305 for accumulating the results of the computation effected for transference to the perforating mechanism 6.

The multiplying commutator 303 (Figs. 9, 14, 16, 17 and 18), comprises an electrical multiplication table in which there are nine sets, designated 306, of nine each of electrical contact disks insulated from each other and divided into twentyseven units of three each, designated by the numeral 301, so adapted that each contact represents one of a series of numbers representing the product of each digit times itself and each other digit running from O1 to 81. Each of the nine sets 306 of nine contact disks represents the numbers 1 to 9 consecutively and is connected to individual brushes leading to the corresponding digit in the multiplicand bank 30l. The contact disks 301 are insulated from and secured to a rotatable shaft 308 journalled in a bearing 309 fastened to a frame 310 (Fig. 9), and a constantly driven hollow shaft 312 having a gear 321 secured thereto for driving the hollow shaft which is in turn journalled in a bearing 32 l.

A magnetic clutch 3ll is provided for connecting the shaft 308 to the constantly driven hollow shaft 3|2 to impart rotative motion thereto. The clutch 3H comprises a toothed member 285 secured to the hollow shaft 312 and a toothed mem her 286 slidably keyed to the shaft 308 and urged into engagement with the toothed member 285 by a spring 281 which engages a shoulder 288 on the toothed member 286 and a collar 289 pinned to the shaft 308 at 290. An armature 29! of an electromagnet 292 mounted on the frame 310 normally holds a pin 293 in a slot 294 formed in the periphery of the toothed member 286. The slot 294 is curved in such a manner that thepin 293 upon engaging it will move the toothed member 286 out of engagement with the toothed member 285. ment of the toothed members 285 and 286 a spring pressed cam roller 295 engages a center stop cam 296 on the commutator shaft 308 to accurately position it. The circuit controlling the clutch 3!! and the means for driving the gear 32! will be described in detail hereinafter.

Each unit 30'! of three contact disks is also provided with an associated feed disk 3l3 (Fig. 16), for making connections with the digit horizontal lines in the multiplicand bank 30!. The contact disks have individual brushes and are so constructed that the position of a contact on half of the circumference represents the unit number of the particular product of two digits and the contact on the other part represents the tens part.

Figs. 16 and 17 show one of the units 301 of three disks 3!4, 3l5 and 3|6, representing the products of multiplying 2 by 1, 9 and 2 respectively. These disk units 30! are similar in construction to sequence switches commonly used in telephone exchange systems. The three copper disks 3, 3!5 and 3|6 are mounted on an insulator 3!! and are electrically interconnected due to the fact that the disks 3!5 and 3!6 are integral and are connected with the disk 3! 4 by means of copper rivets 3l8, passing through the insulator and serving to hold the elements together as the unit 301. The insulator'3l'! is keyed to the commutator shaft 308 and insulates the associated copper disks therefrom. Disk 3I4 has one radial contact 3l9 representing the product 02 of 2X 1 to be engaged by a brush 320 (Fig. 16) at a predetermined point in the rotation of the unit 301; the disk 3! 5 has two radial contacts 326 and 32'! representing the tens digit 1 and the units digit 8 of 2 9 to be engaged by a brush 328 and the disk 3I6 has a contact 329 representing the product 04 of 2 2 to be engaged by a brush 330. A feed brush 33! contacts continuously (a triangular headed arrow (Fig. 14) designates a brush which is always in contact) with the feed disk 313 which is shown in Fig; 16 as being integral with disk 3. The brushes as shown in Fig. 14 are connected through conductors to the multiplicand and multiplier banks 30! and 302. The above described unit was selected for purposes of illustration, and it will be understood that the other units are of a similar construction and are analogous to sequence switches used in telephone systems.

Fig. 18 the enlarged fragmentary schematic of the multiplying commutator, shows the arrangement of the multiplication table for three of the sets 306 representing the digits 1, 2 and 3. The The multiplication table as illustrated follows the series of 1 1,1 9, 1X2, l 3,1 4,1 5, 1X6, 1X7, and 1X8; 2 1, 2X9, 2X2, 2X3, 2X4, 2 5, 2 6, 2 7, and 2X8; 3X1, 3X9, 3X2, etc., wherein each of the contacts represents a particular product. The multipl cation table follows the usual order except that the digit 9 is placed be tween digits 1 and 2 to simplify the interconnecting of the circuits. It will be clear that the multiplication tables for the numbers 4 to 9 inclusive are followed in a s milar manner throughout the length of the multiplying commutator.

Secured to the multiplying commutator shaft. but electrically insulated therefrom. is a control commutator 333, the purpose of which will be clearly understood as the description progresses.

As the pin 293 effects the disengage-' The distributor switch 304 (Fig. 14) is provided for transferring the electrical connections from units to tens, tens to hundreds, hundreds to ten hundreds, etc., as the multiplication progresses to complete an electrical circuit to the proper electromagnets in the accumulator or register 305. The distributor switch is similar in design to selector switches used in telephone systems and comprises in general a shaft 335, an electromagnet 336 for rotating it one step at a time, eight brushes 33'! to 34-! inclusive insulatively mounted upon the shaft, and arcuate banks 35! of twenty-two stationary contacts each adapted for cooperation with said brushes. Six of the brushes 33! to 342 inclusive designate and are connected by conductors to .the units U, tens T, hundreds H, ten hundreds TH, ten thousands TT, and hundred thousands HT, columns in the multiplicand bank 30!. The seventh brush 343 applies ground, progressively to one of the columns indicating units U, tens. T, hundreds H, ten

hundreds TH, ten thousands TT, and hundred thousands HT, in the multiplier bank 302 as the multiplication advances to close the circuit therefrom through the multiplying commutator 303, multiplicand bank 30!, distributor switch 304 and and the accumulator 305 to battery and ground. The purpose of the eighth brush 344 will become apparent as the description progresses. The distributor switches are mounted in the base 2 as are all of the relays forming a part of the multiplying mechanism.

The accumulator 305 registers the products of the multiplication and comprises in this embodiment of the invention 12 individually rotatable contact disks 352 to 363 inclusive, representing units U to hundred billions HB in the final product respectively, with which are associated stationary brushes 364 to 315 inclusive adapted to make a wiping engagement with the contact disks. The position of a brush on a rotated contact disk will indicate the amount of rotation of the disk, and it will be readily understood that the'value of the digit registered on the contact diskwill be proportional to the amount the disk has been rotated.

The rotation of the accumulator contact disks 352 to 363 inclusive is accomplished by an electromagnetically operated means which will now be described: Referring .to Figs. 2 and 9 to 13 inclusive of the drawings, a shaft 38! suitably journalled in the frame work 3l0 has a gear 382 secured thereto meshing with an idler gear 383, which in turn meshes with and drives the gear 32! associated with the commutator shaft 308. The gear 382 meshes with and is driven by an idler gear 396 (Fig. 6) which meshes with the gear 22. Slidably keyed to and rotatable with the shaft 38! is a clutch member 384 (Fig. 12) having a serrated face adapted to engage an associated serrated face on a clutch member 385 upon energization of an electromagnet 386 individual thereto, mounted onthe framework 3l0, and having an armature 38'! bifurcated to engage the surface of an annular depression 388 on the clutch member 384. The clutch member 385 is secured to a sleeve 389 freely rotatable upon the shaft 38! which sleeve also has secured thereto one of the contact disks 352 to 363, a ratchet 390 and a center stop 39!. Associated with the center stop 39! is a roller 392 mounted upon a spring 393 attached'to the framework 3!!) which serves to position the disk accurately in the center of a position when the operation of the disk ceases. The ratchet390 has one tooth thereof considerably higher than the others which higher tooth, upon engaging a pawl "4 associated with the ratchet and mounted upon a disk 30! freely mounted on the sleeve 3", moves the pawl higher than the other teeth move it. The pawl is urged into engagement with the teeth of the ratchet 390 by a coil spring 401 and has formed integral therewith an arm 402 which extends through the framework 310 and engages a surface of a latch 403 associated with one of the contact disks 352 to 363 (Fig. 9) representing the next higher denominational digit in the product. A contractile spring 404 urges the disk 395 supporting the pawl to rotate about the sleeve 309 in a clockwise direction (Figs. 10 and 11) and a spring 405 urges the latch 403 to rotate about its pivot 400 in a counterclockwise direction into engagement with the pawl, the disk 395 being prevented from rotating beyond a predetermined point by an adjustable stop member 401 mounted on the framework 310. Formed integral with the disk 395 is an arm 400 which is engaged by the latch 403 and normally prevents the spring 404 from rotating the disk 303 about the sleeve 333. However, when the pawl 334 engages the high tooth on the ratchet 330, which will occur as the contact disk with which the ratchet is associated passes from the position where it registers the digit 9 to the position where it registers the digit 0, the latch 403 will be moved upwardly releasing the arm 400 and permitting the spring 404 to move the pawl carrying disk 395 in a clockwise direction a distance equal to the amount of rotation necessary to add the digit 1 to the contact disk.

Fixed to the shaft 303 is a cam 409 which engages a camming pin 410 mounted on one end of a lever 4|I, the other end of which has a spring 4|2 secured thereto which tends to rotate the lever 41! and a shaft 413 upon which the lever is mounted in a counterclockwise direction (Fig. 10) This shaft has secured thereto a plurality of levers 4 which, at a predetermined point in each half revolution of the shaft 303, are

moved into engagement with the arms 403 associated with the contact disks 352 to 303 and any of these arms which have been released by their associated latches 403 under actuation of the pawl 304 associated with the contact disk of the next lower denomination, are moved in a counterclockwise direction to advance the associated contact disk a distance representing the value of the unit 1.

In order to facilitate an understanding of the working relationship of the details of the computing mechanism and to afford a more effective means of describing many important functions thereof, an explanation will be given of the steps performed in a specific example such as multiplying 1234.56 by 1234.56.

Let it be assumed that the supply of cards 11 are positioned in the magazine 13, the lowermost or bottom card having punched therein in the columns thereof allotted to the multiplicand the the number 1234.56 and in the columns allotted to the multiplier the number 1234.56. A manually operable start key 4l6 (Figs. 2 and 15) may be operated momentarily to connect ground at 411 through conductors 4 l3 and 419, the windings of the eiectromagnet 40 and a conductor 420 to grounded battery at 420. The momentary closure of the contacts of the starting key 413 will thus energize the electromagnet 40 to connect the clutch members 26 and 21 to drive the cam shaft 43 through one complete revolution.

In rotating through one complete revolution the cams mounted upon the cam shaft will cause the operation of the card feeding mechanism to select the bottom card from the magazine 13, advance it to the movable base plate I53, move the base plate first downwardly and then upwardly to make the contacts indicated by the circles on the multiplier and multiplicand banks 302 and 30! respectively (Fig. 14). The base plate I53 in moving downwardly closes a contact 426 (Fig. 14), to complete a circuit from ground through the windings of a starting relay 421, a conductor 428 to grounded battery at 429, and in moving upwardly with a card thereon, moves the contact spring 211 into engagement with the contact spring 218 (Figs. 6 and 14). The relay 421, upon being energized, establishes a locking circuit for itself from grounded battery 429 through its windings, contact, and armature, conductor 430 to the left hand contact of a release relay 43! to ground. The engagement of the contact spring 213 with contact 211 (Fig. 14), completes a circuit from ground through the left hand contact of the relay 43!, conductor 430, the contact of the starting relay 421, contacts 211 and 213. a conductor 432, a back contact 433 of a relay 434, conductor 435, brush 343, contact 22. on the bank associated with the brush 343, conductor 436, armature of the magnet 336 to grounded battery at 431. This completes a circuit through the distributor switch magnet 336 energizing it so that it will break the contact between the armature thereof and the conductor 436 operating the switch 304 to move all of the brushes 331 to 344 inclusive into engagement with the first contact of their associated banks.

The brush 344 in engaging terminal I of its associated bank connects ground through a contact 438 of a relay 439, a conductor 440 through the brush and a conductor I, contact of the electromagnet 336, winding of the magnet 336 to grounded battery at 431. Simultaneously with the completion of this circuit to magnet 336, the brush 343 will complete a circuit from grounded battery through the relay 439, a relay 442 connected to the horizontal line representing the digit 6 in the multiplier bank 302 by a conductor 443, through the closed contact 6 in the units column of the multiplier bank through a terminal of the arcuate bank of contacts associated with the brush 343, this brush having been stepped onto said contact simultaneously with the movement of the brush 344, through the brush 343, conductors 435, 432 and 430, the left hand contact of release relay 43| to ground.

; The connections effected by the brush 344 tend to advance the distributor switch brushes to the second terminals on their associated banks 351, and the connections effected through the brush 343 tend to operate the relays 439 and 442. However, relay 333 is a slow acting relay so that the circuits completed will cause the relays 439 and 442 to be actuated before the brush 344 leaves the first contact of its associated bank, and the relay 336 is not actuated at this time since the operation of the relay 439 will interrupt the circuit to the relay 333 before relay 336 has time to operate.

Energization of the relay 439 connects ground through its contact 433 to the windings of the electromagnet 292 which actuates the clutch 311 to drive the commutator shaft 303 through one complete revolution. The relay 442, upon being energized, connects ground at 445 through its contacts to the contact disks representing the product of 6 by itself and any other digit. In

the particular problem selected for illustration, ground will be connected from 445 through the conductor 45l to conductors 452 and "land thence to the contact disks representing the product of 6X1 and 6X4, respectively, through the conductor 454 to conductors 455 and 456 and thence to the contact disks representing the product of 6X2 and 6X5, respectively, and through the conductor 451 to conductors 458 and 459 and thence to the contact disks representing the product of 6 3 and 6X6, respectively. Circuits will also be completed to the contact disks representing the product of 6X7, 6x8, and 6x9, but since the numerals '7, 8 and 9 do not appear in the multiplicand, the tracing of the circuits through those contact disks in this particular problem is not necessary.

While some authorities include the zero or cipher with the digits, it is not so included as the term significant digit is used in this application. That is, as herein used in the specification and claims, the expression significant digit is limited to any one of the numbers or symbols, 1, 2, 3, 4, 5, 6, 7, 8 or 9. A zero or cipher (0) is not a significant digit. The energization of the relay 439 to effect operation of the multiplying commutator shaft 308 occurs only for significant digits entered and stored in the multiplier factor bank 302. When a cipher or zero occurs in an entered multiplier factor, regardless of the denominational position of the cipher, the multiplying commutator 303 is not actuated and the brush 343 automatically steps to the next higher denominational column contact in the bank 302, thereby avoiding any idle computing cycles.

At predetermined points in the rotation of the commutator shaft 308, the grounded brushes will engage conducting portions on the contact disks to thereby connect ground through the contact disks to their associated conductors leading to the multiplicand bank 30l. In the first half revolution of the commutator shaft the contacts representing the units part of the product will engage the brushes and in the second half revolution the contacts representing the tens part will engage the brushes. Thus, the contact disk representing the product of 6X6 in the first half revolution would have a contacting portion at the point on its surface which would leave six of nine possible positions yet to pass the brush,

and in the second half revolution would have a contacting portion at the point on its surface which would leave three of the nine possible positions yet to pass the brush.

When the contacting portions of the contact disks engage .the grounded brushes they will through the lower left hand brushes, which are always in contact with a conducting portion of the contact disk, connect ground through the multiplicand bank to the windings of a plurality of holding relays 460. The other end of the windings of the relays 460 are connected to grounded battery 46I and the relays will thereupon be energized to attract their armatures connecting ground through a conductor 462 and a brush 463 which engages the control commutator 333, completing a locking circuit whichmaintains the relays 460 energized until the end of each half revolution of the commutator shaft. The control commutator 333 is so constructed that the brush 463 will be connected to ground therethrough at all times except at the end of each half revolution of the commutator shaft when the ground connection therethrough will be broken.

There is provided a relay 460 for each denomi- N national column in the multlpllcand bank 3M and upon energlzatlon of the relays 480 they will supply ground through their contacts and the multiplicand bank 301, conductors 484 to 469 inelusive, to the brushes 331 to 342 inclusive, respectively. These brushes 331 to 342 now being in engagement with the first contact on their associated banks will connect ground through the brushes, conductors 416, 411, 418, 419, 480, and 48 I, to one side of the windings of electromagnets 386, representing the units U, tens T, hundreds H, ten hundreds TH, ten thousands TI, and hundred thousands HT, denominational contact disks on the accumulator respectively. The other side of the windings of the electromagnets 386 are connected to battery and ground at 482 and upon ground being supplied thereto primarily through the contact disks of the multiplying commutator and thereafter being connected thereto through the holding relays 460 which derive ground through the control commutator 333, the electromagnets 386 will remain operated until the control commutator breaks contact to ground at the end 'of each half revolution of the commutator shaft.

Referring back to the particular problem selected for illustration, during the first'half rev lution of the commutator shaft, the contact disks on the commutator shaft 308 associated with the digit 6 of the multiplier and the digits 6, 5, 4, 3, 2. and 1 of the multiplicand will complete circuits from ground at 445 through the contacts of the relay 442 associated with the digit 6 in the multiplier at the position of the disks which will transmit the digits 6, 0, 4, 8, 2, 6, representing the units part of the product, through the units U, tens T, hundreds H, ten hundreds TH, ten thousands TT, and hundred thousands HT, brushes 331 to 342 in the distributor respectively which, being connected through the conductors 416 to 481 inclusive to the units U, tens T, hundreds H, ten hundreds TH, and hundred thousands HT, electromagnets 386, will effect the rotation of the disks 352 to 351, an amount proportional to the length of time which the electromagnets 386 associated with the units U to hundred thousands HT accumulator disks are energized. Thus it will be apparent that the position of the accumulator disks 352 to 351 respectively will indicate the digit value 6, 0, 4, 8, 2, 6, respectively, as the control 7 commutator 333 breaks the contact to ground, thereby releasing all of the electromagnets 386 and their associated holding relays 460.

As the control commutator 333 breaks contact with the brush 463, a brush 483 associated therewith makes contact with a conducting portion thereof to supply ground to the winding of the distributor switch magnet 336 which will thereupon be actuated to advance the brushes 331 to 344 inclusive into engagement with the second contact on their associated banks of contacts. The brushes 343 and 344 are of what is known as the bridging type; that is, they. do not completely disengage from one contact before engaging the next succeeding contact, and as a result of this construction, the relays 439 and 442 do not release since the brushes 343 and 344 make contact with the second contact in their associated banks before releasing contact with the first contact in the associated banks. The commutator shaft 308 will continue to rotate and at this point in a cycle of to 353 one unit provided the contact disks 352 to 352; that is, the contact disk representing the next lower denominational register, has passed from indicating the digit 9 to indicating the digit 0.

The effect of the above described cam action is to add one to those contact disks to which a carry of one in the process of multiplication should be eifected. It will be seen that no disk can have passed over nine in the primary operation just described.

As soon as the carry motion has been effected, the second half revolution of the commutator shaft 388 takes place and the contact disks mounted thereon connect ground through the holding relays and the brushes 331 to 343 of the distributor switches which have been moved into association with the second contact on their associated banks of contacts, through the conductors 411, 418, 419, 480, 48l, and 485 to the electromagnet 388 associated with the registers representing tens, hundreds, ten hundreds, ten thousands, hundred thousands, and millions in the accumulator. bank of contacts associated with the brushes 343 are interconnected, the tens part of the product of multiplying the number 1234.56 by 6 thereof will be sent to the accumulator contact disks 353 to 358. The tens part of the product of 6X 1234.56 is 011233 and the ground connection will be maintained to the electromagnets 386 a length of time sufficient to rotate their associated contact disks to the point where they will add 3 to the tens, 3 to the hundreds, 2 to the ten hundreds, 1 to the ten thousands, l to the hundred thousands, and 0 to the millions contact disks 353 t 358 respectively, whereupon the ground connection through the control commutator 333 will again be broken and the distributor switch magnet 335 energized to step the brushes 331 to 344 into engagement with the third contact on their associated banks of contacts, and the camming action incident to carrying one into denominational registers of the accumulator will be effected where necessary. As the brush 343 leaves the second contact on its associated bank 35!, the ground connection t the relay 442 associated with the digit 6 in the multiplier will be broken, de-energizing the relay.

It will be apparent from the foregoing that at the end of the first half revolution of the commutator shaft 308 the contact disks in the accumulator which represent the units U, tens T, hundreds H, ten hundreds TH, ten thousands TI, and hundred thousands HT part of the prodnot will show a partial product of 628406. Since none of these contact disks has passed from 9 to 0, no carry is required and therefore the carry interval is no import. The second half revolution of the commutator shaft transmits the tens part of the product to the contact disks in the accumulator associated with the tens to the millions denominations, and as mentioned hereinbefore, transmits 3, 3, 2, 1, 1, 0, to the contact disks tens to millions respectively.

It will be noted that the contact disk representing the ten hundreds denomination, at the end of the first half revolution of the commuta tor shaft, is standing on 8, and that in the second half revolution a digit of the value of two is transmitted thereto. This condition requires that a carry be made, and as the disk representing the ten hundreds passes from registering 9 to the position where it registers 0, the latch 403 (Figs. l0, 11, 12 and 13), will be released and at the end or the second half revolution of the shaft a digit of the value of 1 will be sent into the Since the first two contacts on the,

contact disk representing the ten thousands denomination. Simultaneously with the addition of one to the contact disk representing the ten thousands denomination, the brushes 331 to 344 are advanced into engagement with the third contact on their associated banks, as previously described, and the brush 463 breaks contact releasing the holding relays 460 and the product registered on the accumulator contact disks will be 0740736.

The brushes 331 to 344 having been advanced into engagement with the third contacts on their associated banks, the following circuits will be completed: Brush 343,' which is grounded through the contact of the starting relay 421 and the contact 433 of the relay 434, will connect ground through the tens column of the multiplier bank 382 through the closed contact 5 to the relay 442 associated with the digit 5, through the relay 439 to grounded battery thereby to energize the relay 442 associated with the digit 5 of the multiplier and complete circuits similar to those completed by the relay 442 associated with the digit 6 in the units column of the multiplier bank. As the brush 343 moved out of engagement with the second contact on its associated bank, the ground connection to the relay 442 associated with the digit 6, in the multiplier bank was broken and the relay de-energized, but the relay 439 was maintained operated due to the bridging action of brush 343 and the commutator shaft 308 continues to rotate since the relay 43% was not released. The process of transmitting electrical connections to the electromagnets 386 of the accumulator continues in the same manner as it did for transmitting the product of 123456 by 6, the step by step movement of the brushes transmitting the actuating currents to the electromagnets 386 precisely as described in connection with the multiplied digit 6, except that the brushes 331 to 342 transmit the actuating current to different register dials in the manner described hereinbefore except where a multiple carry is to be effected.

In the problem selected for illustration, a multiple carry is effected in multiplying the multiplicand 123456 by the multiplier digit 4 since the contact disks units to millions have stored therein 6, 3, 5, 3, 1, 9, 6, and upon the multiplying commutator sending the units part of the product oi 4Xl23456 to the contact disks hundreds, ten hundreds, ten thousands, millions and ten millions, the hundred thousands and millions contact disks will each pass from the position where they indicate 9 to the position where they indicate l and 4, respectively, and in so doing will each separately actuate the carry mechanism so that a digit of the value of 1 will be entered in the next higher denominational registers. Specifically, the accumulator contact disks 352, 353, 354, 355, 358, 351 and 358 will have registered therein 6, 3, 5, 3, l, 9, and 6, respectively, and the accumulator contact disks 354. 355, 356, 351, 358 and 359 will have the digits 4, 0, 6, 2, 8 and 4, respectively, sent thereto. The accumulator contact disks 351 and 358 will pass through the positions where they indicate 9, and in so doing will trip the latch mechanisms and prepare the disks 358 and 359 to receive the digit 1 when the carry operation takes place as explained in detail hereinbefore, for a single carry.

In order to further explain the operation oi the carry mechanism, let it be assumed that, the units, tens, hundreds, ten hundreds and ten thousands accumulator contact disks are in the positlon where they indicate that the digit 9 is stored therein in each denomination, and that the mechanism is so operated that the digit 1 is transmitted to the units accumulator contact disk. When the numbers 99999 are stored in these registers, the high tooth of the ratchet 390 will be adjacent the pawl 394 in each of the registers affected and further when the digit 1 is added to the lowest register, its associated dial' will advance on tooth, causing the high tooth to lift the pawl 394 which will in turn raise the latch 403 associated with the next higher or tens register, thereby to permit the pawl 394 of the tens register to .be moved in a clockwise direction (Fig. 11) by the contractile spring 404. The pawl 394 in the tens register, in moving in a clockwise direction (Fig. 11), will pass over the high tooth of the ratchet in the tens register, and in so doing will release the latch 403 of the hundreds register and the spring 404 of the hundreds register will move the disk 395 of the hundreds register in a clockwise direction, and in so doing the pawl 394 of the hundreds register will pass over the high tooth of the ratchet 390, releasing the latch 403 of the ten hundreds register which will in turn permit the spring 404 of the ten hundreds register to move the disk 395 of the ten hundreds register in a clockwise direction, and the pawl 394 of the ten hundreds register will be drawn over the high tooth of the ratchet 390 of the ten hundreds register to release the latch 403 of the ten thousands register which will permit the spring 404 of the ten thousands register to move the disk 395 of the ten thousands register and it in turn will release the latch and move the pawl of the hundred thousands register so that when the shaft M3 is rocked in a clockwise direction, the pawls 394 of the tens, hundreds, ten hundreds, ten thousands and hundred thousands registers will move their associated ratchet wheels a distance suflicient to add 1 to each of the contact disks 352 to 351, inclusive, so that after the carry cycle takes place the contact disks 352, 353, 354, 355, 356, and 351 will have 00000 and 1, respectively, stored therein. It will be noted at this time that the time allowed for the operation of the latches and pawls of the carry mechanism is sufficient to permit any possible number of multiple carries to be effected within the limits of the machine.

All of the parts function as described herein- Q before until all of the brushes 331 to 343 stand on the thirteenth contacts of their associated banks, at which time the product 15241383936 of 123456 123456, will be registered on the accumulator contact disks 362, 36!. 360, 359, 358, 351, 356, 355, 354, 353, and 352, respectively. When the brushes 331 to 344 inclusive engage the thirteenth contact in their associated banks of contacts, the brushes 33'! to 343 will be resting on contacts not connected in circuit to any part of the apparatus, and therefore the connection through the brush 343 and one of the relays 442 to the relay 439 will be broken, removing ground from the relay 439 resulting in its deenergization. The de-energization of the relay 439 breaks the circuit which energizes the electromagnet292, thereby stopping the rotation of the multiplying commutator shaft 308. The brush 344 in engaging the thirteenth contact on its associated bank connects ground through the armature 438 of the relay 439, conductor 440, the brush 344, a conductor 481 to end of which is connected through a contact disk 488 mounted upon the cam shaft 48 (Figs.

3, 6 and 15), to grounded battery at 428. The completion of this circuit will actuate the release relay 43!, causing it to attract its armatures thereby to connect ground through a conductor 489 (Figs. 14 and 15) connected to the conductor 484 through the windings of the electromagnet 336', energizing it. Ground will be connected through the right hand contact of the release relay 43!, a conductor 490 to the conductor 4I9, thence through the winding of the electromagnet 40, a conductor 420 to grounded battery at 428,

energizing the magnet 40 and thereby causing the cam shaft 48 to be rotated through one complete revolution. As the shaft 48 moves out of its normal postion, the connection of relay 43! to battery is broken at contact disk 488, releasing the relay, removing ground from and releasing electromagnet 336 and thus advancing the brushes 331 to 344 to their fourteenth terminal.

nected contacts I to I2 and I4 to 22 of its associated bank through the conductor 44!, contact of the relay 338, a conductor 49! to the winding of the electromagnet 336 thereby causing it to be actuated eight times in rapid succession to return the brushes 331 to 344 back to their normal position. The operation of the circuit just described will reset the distributor switch 304 for the reception of a second problem.

At this point the accumulator contact disks units to ten billions will have registered therein the product of 1234.56 l234.56 or TBBHM TMMHTTTTHHTU 1, 5, 2, 4, 1, 3, 8, 3, 9, 3, 6, and the apparatus is ready to perform its last function, the perforating of the product in the same record card which had previously been positioned beneath the sensing heads. As the electromagnet 40 was energized as described at the end of the multiplying cycle, the card which had been resting upon the movable base plate I53 will be advanced by the card feed rollers into engagement with the card stop 202 (Figs. 5, 7 and 8), in the perforating mechanism 5,

whereupon the upper rollers I18 and I19 will be disengaged from the card as described hereinbefore in connection with the card feeding mechanism 3. v

Simultaneously with the advancement of the card into engagement with the card stop 202, the cam 65 mounted upon the cam shaft 48 will actuate a cam roller 50! associated therewith (Figs. 3 and 5). The cam roller 50! is mounted upon an end of a bell crank lever 502 pivoted upon the crank supporting shaft 2I1 and upon actuation by the cam 85, the bell crank lever 502 will be rotated about the shaft 2 I1 in a counterclockwise direction to cause the vertical arm thereof to move upwardly. Attached to the end of the vertical arm of the bell crank lever 502 is a rack the windings of the release relay 43!, the other 503 which meshes with a gear 504 mounted upon 

